The Aether appears to alter reality (it was going to bring about Malekith's darkness over all worlds, so I think that makes it the Reality Stone. The Tesseract was a portal throughout the cosmos, so that appears to be the Space Stone. Now, Thanos GAVE Loki that spear. He didn't forge it from the Tesseract. That would tell me Thanos has one of the stone himself (the Mind Stone) which he helped harness to give Loki that spear.

Someone said something about Red Skull obtaining a stone. That could come into play in C:TW if one of my Cap 2 theories is true in regard to Redford potentially being the Red Skull in disguise, ala Dell Rusk, happens. He very well could have a stone himself. If GotG introduces another Infinity Stone, then we definitely have 3, possibly 4, accounted for prior to AoU! I am thinking we're getting Thanos Quest basically!!!! All roads end with Thanos acquiring all the stones and becoming a god